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Firm GuideHFT Interview
April 202613 min read

Virtu Financial & Optiver: Quant Interview Expectations

A side-by-side guide to two of the most technically demanding HFT firms — firm overviews, interview stages, question types, cultural differences, compensation benchmarks, and preparation strategies.

James Alderton, FRM

Quantitative trading researcher · 11 years across options market-making and algorithmic execution at HFT firms in New York and Amsterdam · MS Financial Mathematics, NYU Courant

Former interview coach for quant candidates entering European and US market-making roles. Regular contributor to Myntbit's HFT interview series.

Virtu: Founded

2008

NASDAQ: VIRT

Optiver: Founded

1986

Employee-owned

Optiver Filter

80 in 8

Mental math test

Offer Rate

1–3%

Both firms

Virtu Financial and Optiver occupy a distinct tier within the quantitative finance landscape. They are not as frequently covered in prep guides as Jane Street or Citadel Securities — yet both firms are among the world's most sophisticated market-making operations, and both offer highly competitive careers for quantitative professionals.

What makes them distinct is their focus: Virtu is the paradigmatic technology-first market-maker, operating at scale across thousands of instruments globally; Optiver is the options specialist, with a 40-year track record in options market-making and a unique European cultural heritage. The interview styles at both firms reflect these differences — and knowing what each firm values before you walk in is a meaningful edge.

This guide covers both firms in depth: firm overviews, interview stages, representative question types, and actionable prep tips for each.

Part 1: Virtu Financial

Virtu Financial was founded in 2008 by Vincent Viola and Douglas Cifu in New York City. Unlike many peer HFT firms, Virtu is publicly traded on NASDAQ (ticker: VIRT), which gives it an unusual level of public transparency for an industry known for opacity. In its 2015 S-1 filing, Virtu famously disclosed that it had been profitable on all but one trading day in a six-year span — crystallizing the public understanding of what technology-driven market-making can achieve.

Virtu operates as a global electronic market maker, providing liquidity across equities, fixed income, currencies, commodities, and derivatives in over 50 countries and across more than 235 trading venues. Its core competitive advantage is its execution and risk-management technology stack — not a strategy-first research shop, but an infrastructure-first trading operation.

Key Facts: Virtu Financial

Founded2008 by Vincent Viola & Douglas Cifu
ExchangeNASDAQ: VIRT (publicly traded)
OfficesNew York, Dublin, London, Singapore, Sydney, Hong Kong, Austin
Employees~1,000
Markets235+ venues, 50+ countries
Notable dealAcquired KCG Holdings (2017)

Roles at Virtu Financial

Quantitative ResearcherPython, statistics, market microstructureStrategy research, signal development
Quantitative DeveloperC++, low-latency systemsExecution infrastructure, order management
Algorithm DeveloperC++/Python, market data systemsMarket-making algorithms
Data ScientistPython, ML, data engineeringAnalytics, quantitative research support

The Virtu Interview Process — Stage by Stage

1

Resume Screen

Quantitative academic backgrounds (math, CS, physics, financial engineering), systems programming experience, and market microstructure interest filter the initial pool.

2

Online Assessment (30–60 min)

Coding (Python/C++): data structures and numerical computing. Quantitative reasoning: probability and statistics. Basic market microstructure questions.

3

Technical Phone Screens (1–2 rounds)

45–60 min each: coding problem in Python or C++, two to three probability/statistics problems, resume deep-dive on quantitative projects, microstructure scenario questions.

4

Superday (3–5 Interviews)

Systems coding, probability and statistics, market microstructure depth, quant finance knowledge (options/risk), and fit interview.

Question Types at Virtu Financial

Coding Questions (Python/C++)

Implement a rolling median in O(log n) using two heaps
Given a stream of price ticks, compute the VWAP over a sliding window with efficient updates
Parse a raw FIX protocol message and extract order fields
Design a rate-limiter for an API endpoint with specified throughput constraints

Probability and Statistics

You observe 100 coin flips, 60 of which are heads. Construct a 95% confidence interval for the bias parameter p.
Given a geometric Brownian motion with μ = 0.08 and σ = 0.25, what is the expected log return over 1 year? What is the probability that the stock price exceeds 1.5× its current value in 2 years?
What is the variance of the sum of n i.i.d. random variables with variance σ²? How does this change if the variables are correlated with coefficient ρ?

Market Microstructure

Explain adverse selection in the context of a market maker. How does a market maker protect itself?
What is the Kyle lambda (price impact model) and how is it estimated from market data?
A large institutional order hits your market. How do you update your quotes before and after the trade?

Virtu-Specific Prep Tips

Study market microstructure seriously

Read Glosten-Milgrom, Avellaneda-Stoikov, and the intuition behind Almgren-Chriss. Understand adverse selection, inventory risk, and execution optimization at the level where you can reason about tradeoffs quantitatively.

Python performance matters

Write code as if performance matters — use NumPy vectorized operations, avoid unnecessary loops, and show awareness of memory layout. Virtu interviewers notice candidates who write naturally efficient code.

Be ready to discuss public Virtu data

Because Virtu is publicly traded, you can read their quarterly earnings calls, 10-K filings, and S-1. Know their capture rate trends, the KCG acquisition rationale, and payment for order flow dynamics.

Part 2: Optiver

Optiver was founded in 1986 in Amsterdam, making it one of the oldest active HFT and options market-making firms in the world. The firm began as a single trader on the Amsterdam Options Exchange and built into a global options market-making operation spanning equities, fixed income, ETFs, commodities, and foreign exchange.

Optiver is entirely employee-owned — no external investors, no PE backers, no public listing. The firm is known for its long-term perspective, its unusually strong Dutch-heritage culture (structured, collaborative, direct), and its genuine expertise in options market-making. The options focus distinguishes Optiver from Virtu: while Virtu trades across asset classes with a generalized model, Optiver has built deep specialization in volatility surface modeling and derivatives pricing.

Key Facts: Optiver

Founded1986, Amsterdam
Ownership100% employee-owned
OfficesAmsterdam (HQ), Chicago, Sydney, Shanghai, Taipei, London, New York
Employees~2,000
SpecializationOptions market-making, volatility surfaces
Famous filterThe '80 in 8' mental math test

Roles at Optiver

TraderMental math, probability, options theoryOptions market-making, volatility trading
Quantitative ResearcherStatistics, ML, Python/C++Signal research, model development
Software DeveloperC++, distributed systemsTrading infrastructure
Risk ManagerDerivatives risk, statisticsPosition risk management

The Optiver Interview Process — Stage by Stage

1

Application and Sourcing

Campus programs at Amsterdam, Delft, ETH, MIT, U Chicago, CMU, Imperial. Strong pipeline from math olympiad and competitive programming backgrounds.

2

The '80 in 8' Mental Math Test

80 arithmetic problems in 8 minutes without a calculator. ~40–50% of candidates fail to meet Optiver's threshold. This is a hard filter, not a courtesy screen.

3

Numerical Reasoning + Personality Assessments

SHL-style numerical reasoning (harder than standard) plus a situational judgment or personality inventory.

4

Video/Phone Interview (30–45 min)

Live mental math, two to three probability problems, options/trading concepts for the Trader track, and cultural fit discussion.

5

Superday (Amsterdam, Chicago, or Sydney)

Advanced probability, options theory (Trader track), live mental math round, market-making simulation, coding assessment, and final HR interview.

Question Types at Optiver

Mental Arithmetic — The 80 in 8 Format

Optiver's mental math emphasis is the highest of any major HFT firm. 6 seconds per problem maximum. Expect:

What is 47 × 83?(Answer: 3,901 — compute in under 8 seconds)
What is 144 ÷ 16? What is 7/9 as a percentage to two decimal places?(Fractions and division under time pressure)
A stock moves from $84 to $91. What is the percentage gain?(Compound computation: (91-84)/84 × 100)

Probability and Statistics

“You flip a fair coin until you get two heads in a row. What is the expected number of flips?”

Let E = expected flips from any point. E = 1 + (1/2)(1 + E) + (1/4)(0) → solving: E = 6

“Cards are drawn from a shuffled 52-card deck. You can stop at any time and win $1 if the next card is red. What is the optimal stopping strategy?”

“A drunk takes steps of ±1 with equal probability starting at 0. What is the expected number of steps to reach +3?”

Options Theory (Trader Track)

Walk me through the derivation of put-call parity. What are the assumptions required?
If a stock moves up $1, what happens to the value of an at-the-money call? An in-the-money call? Explain in terms of delta.
Why does implied volatility vary across strikes (the vol smile)? What does this tell you about the market's implied distribution?
You are quoting a delta-neutral straddle. Overnight, realized volatility picks up significantly. What happens to your P&L? Why?

Market-Making Simulation (Legendary)

Optiver's market-making game is legendary among HFT interview candidates. Common formats:

The Dice Game: Interviewer rolls a concealed die; candidates make markets and update quotes as partial information arrives (e.g., 'the result is even')
The Jar Game: A jar contains an unknown number of marbles; candidates sample and market-make the count, narrowing spreads as more samples arrive
Stock Simulation: Multi-round competitive trading where candidates quote bid-ask spreads, manage inventory, and update prices based on trade flow

Evaluation criteria: rational quote updates, controlled inventory, disciplined spread management, and verbalizing the reasoning behind every price change.

Optiver-Specific Prep Tips

The '80 in 8' is pass/fail — treat it first

Before any other prep, time yourself with a strict 8-minute clock on 80 mixed arithmetic problems. If your pass rate is below 80%, address that before anything else.

Study options theory with real market context

Optiver's options questions are not purely textbook. Study skew, term structure, and the relationship between realized and implied volatility. Hull's Options, Futures, and Other Derivatives is a good foundation; Taleb's Dynamic Hedging provides the practitioner intuition.

Practice verbalizing market-making logic

The most common failure mode is silent updating — candidates change their quotes but do not explain why. Practice with a partner: have them give you information incrementally and narrate every quote adjustment.

Understand Optiver's cultural values

Optiver has a distinctive Dutch-rooted culture: direct communication, intellectual honesty, and genuine interest in markets. They look for candidates excited about options market-making, not just chasing compensation.

Your Preparation Plans

For Virtu Financial — 8-Week Plan

Wk 1–2

Market microstructure foundations

Adverse selection, Kyle lambda, order book dynamics, Glosten-Milgrom, Avellaneda-Stoikov

Wk 3–4

Coding: Python performance + C++ algorithmic prep

LeetCode medium/hard, NumPy vectorization, data structure problems, performance-aware Python

Wk 5–6

Probability and financial statistics

Stochastic processes basics, Shreve Vol I, GBM intuition, confidence intervals, hypothesis testing

Wk 7

Virtu-specific research

Read earnings calls, 10-K filings, KCG acquisition rationale, payment for order flow dynamics

Wk 8

Mock technical interviews

Full mock superdays across coding, probability, and microstructure

For Optiver — 10-Week Plan

Wk 1–3

Mental arithmetic drilling

20–30 min/day minimum, every day. Timed arithmetic: multiplication, fractions, percentages. Build to 80/8 min reliably.

Wk 4–5

Probability: expected value, conditional probability, stopping times

Zhou Green Book, Mosteller Fifty Challenging Problems, random walk recurrences, Markov chains

Wk 6–7

Options theory: Greeks, put-call parity, vol surfaces

Hull chapters 17–21, straddles/strangles/straddle P&L, implied vs realized vol, skew intuition

Wk 8–9

Market-making simulation practice with a partner

Optiver-style dice and jar games, narrate every quote adjustment, manage inventory consciously

Wk 10

Full mock superday + weak-area drilling

End-to-end practice, timed arithmetic review, options theory rapid-fire questions

More Firm Guides

Frequently Asked Questions

Final Thoughts

Virtu Financial and Optiver are two of the most technically demanding employers in quantitative finance — and two of the most rewarding for candidates who match their respective profiles.

Virtu rewards the candidate who thinks like a systems engineer: someone who understands how markets work at the infrastructure layer, can write performant code, and appreciates the operational challenge of scaling a market-making model across thousands of instruments globally.

Optiver rewards the candidate who thinks like an options specialist: someone who has internalized the mathematics and market dynamics of derivatives, can compute quickly and precisely under pressure, and genuinely enjoys the probabilistic reasoning at the core of market-making.

Practice Virtu & Optiver-Style Questions

Myntbit offers 650+ curated problems calibrated to market-making, options theory, probability, and mental math — the exact skill set these firms test, with firm-specific difficulty calibration.